1. Field of the Invention
This invention relates generally to writing instruments capable of electronically counting the number of marking strokes, and pertains more particularly to a ballpoint pen in which the counting circuitry is reset by means of a gravity switch contained within the pen.
2. Description of the Prior Art
Writing instruments capable of counting the number of marks are not completely new. Examples of such devices are disclosed in U.S. Pat. No. 3,064,888, issued to Robert L. Van De Mark on Nov. 20, 1962 for "COUNTING PEN" and West German Pat. No. 2,542,831, issued to Plath et al on Apr. 7, 1977 for "BALL PEN WITH INTERNAL ELECTRONIC COUNTER." Insofar as we are aware, the alluded to patented devices are capable of performing their intended counting function. However, the pens are quite bulky, cumbersome, relatively costly and sufficiently complex so as to militate against any general use and adoption of such instruments. The German patent discloses a larger than normal ballpoint pen containing a battery-powered internal electronic calculator having an external on-off switch and an external reset button. The German pen lacks an internally disposed gravity switch for resetting the calculator. The counting marker disclosed in said U.S. patent utilizes both an external counting mechanism and an external battery. Hence, again there is no gravitational reset feature.